JPS59185331A - Electron beam sensitive resist substance - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION BACKGROUND OF THE INVENTION Field of the Invention The present invention relates to electron beam sensitive resist materials which are particularly useful as information recording media.

(4) Description of the prior art Octadecyl vinyl ether-maleic anhydride l=l
The unsaturated ester derivative of the copolymer has about 10- to 5×10
Although exhibiting an electronic sensitivity of Coulomb/crn2, the contrast of these materials is generally less than about 1.2, so submicron images cannot be recorded. Approximately 80 Ke
Other derivatives, i.e. hydroxyethylpyrrolidone (HEP) esters of the same copolymer, have a sensitivity of only about 10-4 coulombs/- to electron radiation when irradiated with electrons with energy less than V. do not have.

According to the literature, mixtures of electrosensitive polymers with widely different sensitivities have sensitivities intermediate between the values of their components, and any of the components exhibits significantly poor core contrast and therefore resolution. is known to be expected. The inventors have determined that this is not the case for mixtures of said hydroxyethylpyrrolidone derivatives and mixtures of reaction products of unsaturated ester derivatives. Furthermore, 1(6) the inventors have more clearly confirmed that the contrast of such resists is significantly improved to provide resolutions of less than 0.5 micrometers.

This contrast increase in the present invention is achieved by alkyl vinyl ether-maleic anhydride e typical 0 form and hydroxyethyl acrylate, hydroxyethyl methacrylate, 3-hydroxyglobyl acrylate, 3-hydroxypropyl methacrylate.

Hydroxyalkyl or allyl acrylates such as 4-hydroxybutyl acrylate, 4-hydroxybutyl methacrylate or reaction products with glopargyl alcohol or pentaerythritol triacrylate, and N-hydroxyalkylamides and N-aminoalkyl This is achieved by a resist made by mixing a reaction product of a compound selected from the group consisting of amides and an alkyl vinyl ether-maleic anhydride copolymer to form a novel half-ester copolymer.

SUMMARY OF THE INVENTION - This invention relates to g-ionizing radiation materials with high contrast and high sensitivity. product and a reaction product of a hydroxyalkyl terminally unsaturated compound and an alkyl vinyl ether-maleic anhydride copolymer. A typical substance is produced by mixing a reaction product of hydroxyethylpyrrolidone and an octadecyl vinyl ether-maleic anhydride copolymer with a reaction product of hydroxyethyl acrylate and a typical octadecyl vinyl ether-maleic anhydride copolymer. Let's go.

In this invention, N-hydroxyalkyl amides such as hydroxyethylpyrrolidone and hydroxyalkyl acrylates such as hydroxyethyl acrylate are each separately combined with long chain alkyl vinyl ether-maleic anhydride copolymers, preferably octadecyl vinyl ether. - with about 10 to 20 carbon atoms in the alkyl chain, such as maleic anhydride copolymers, and then mixed with each other. Preferably, the reaction product of the hydroxyethylpyrrolidone mixture and the reaction product of the hydroxyethyl acrylate mixture are mixed in a molar ratio of 40:60. Products soluble in common solvents such as toluene readily form smooth coatings on substrates.

During electron beam irradiation, the resist of this invention cross-links at low electron density to form an insoluble polymer (negative resist), which adheres to the substrate, is non-stick, and is easy to handle. It's easy. The unirradiated resist can be easily dissolved and removed to form a desired resist pattern.

3 Detailed Description of the Invention The electron beam-sensitive material of the present invention has the following characteristics: (1) high sensitivity to electron beam irradiation; (2) insensitivity to visible light or near ultraviolet radiation; (8) smooth surface on a substrate. (8) ease of forming a film; (4) resistance to wet or dry etching of the cross-linked polymer;
(5) The material in the unirradiated areas can be easily dissolved and removed with conventional solvents; (6) Formation of negative resist patterns: (7) Excellent contrast and resolution; (8) Thermal stability; (9) (10) minimal dark reaction after irradiation. It is surprising that these advantageous properties of the materials of the invention are obtained. This is because this material has a lower amount of terminal unsaturation in the ester groups compared to resists presented in the prior art, approximately 26%, and its sensitivity is much greater than the average sensitivity between the two. It is. The mechanism by which the resists of this invention possess these advantageous properties and characteristics is currently unknown. However, it is believed that the amide and acrylate groups form a charge transfer complex that lowers the energy required for cross-bonding of the acrylate groups with adjacent chains.

This explanation is supported by experimental evidence that sensitivity increases with molar ratios approaching 1:1, which is considered the optimal amide to acrylate ratio for the formation of such charge transfer complexes.

In one example of the invention, the substance of this invention is a reaction product of a mixture of an alkyl vinyl ether-maleic anhydride copolymer JN-hydroxyalkylamide, and a hydroxyalkyl acrylate compound and an alkyl vinyl ether-maleic anhydride copolymer. It is produced by mixing the reaction products of a mixture of. A thin film of the polymer is then applied to a suitable substrate, such as a chromium-plated glass or quartz mask substrate, a silicon wafer or a conductive polyester substrate, and irradiated with various charge densities.

The hydroxyalkylamide component is a hydroxyalkylpyrrolidone, such as hydroxyethylpyrrolidone, hydroxyglobilpyrrolidone, hydroxybutylpyrrolidone, hydroxyethyl-ε-caprolactam, human xypropyl-ε-caprolactam, hydroxybutyl-pyrrolidone.
N-hydroxyalkyl amides such as ε-caprolactam, N-hydroxyethylacetamide, N
-N-hydroxyalkyl linear amides such as -hydroxyethylpropionamide and the like.

The terminally unsaturated component is allyl or propargyl alcohol or hydroxyalkyl acrylate.

Examples include hydroxyethyl acrylic acid or methacrylate, 8-hydroxyglobyl acrylic acid or methacrylate, acrylic vt+ includes 4-hydroxybutyl methacrylate, pytaerythritol triacrylate, and the like.

In other embodiments of the invention, the material is a reaction product of an alkyl vinyl ether-maleic anhydride copolymer and an N-aminoalkyl amide, and a mixture of a hydroxyalkyl acrylate compound and an alkyl vinyl ether-maleic anhydride copolymer. The above substances are produced and prepared by mixing the reaction products of . A thin film of this material is then applied to a suitable substrate such as a chromium-plated glass or quartz mask substrate, a silicon wafer or a conductive polyester substrate and irradiated with various charge densities.

The aminoalkylamide component is an aminoalkylpyrrolidone, such as aminoethylpyrrolidone.

Aminopropylpyrrolidone, aminobutylpyrrolidone,
Aminoethyl-ε-caprolactam, aminopropyl-
Either N-aminoalkyl cyclic amides such as ε-caprolactam, aminobutyl-ε-caprolactam etc. or N-aminoalkyl linear amides such as N-aminoethylacetamide, N-aminoethylpropionamide etc. be.

EXAMPLE Preparation of Rugisto Materials Reaction product of a mixture of 40 mole percent hydroxyethyl pyrrolidone and octadecyl vinyl ether-maleic anhydride copolymer and 60 mole percent hydroxyethyl acrylate and octadecyl vinyl ether-maleic anhydride copolymer This was done by combining the reaction products of the mixture with

The unsaturated ester derivative is hydroxyethyl acrylate (
In this case, the following data were obtained:

(12) Amount Amount Sensitivity HKA ester (%l HEP ester (%l
l06 coulombs/crn2 contrast 100
-0.46 1.
050 50 0.51
],,725 75
0.86 2.5- 100
100 - The increase in contrast obtained with these mixtures made it possible to resolve submicron structures.

The high contrast achieved without severe loss of sensitivity provides an electronic recording medium useful in submicron, electron beam lithography techniques.

Claims (1)

[Scope of Claims] 1. A reaction product of a mixture of an alkyl vinyl ether-maleic anhydride copolymer and a terminally unsaturated alcohol, and a compound selected from the group consisting of N-hydroxyalkylamides and N-aminoalkylamides. An electron beam-sensitive resist material characterized in that it is a combination of a reaction product obtained by mixing an alkyl vinyl ether-maleic anhydride copolymer with an alkyl vinyl ether-maleic anhydride copolymer. The resist according to claim 1, wherein the N-hydroxyalkylamide is an N-hydroxyalkyl cyclic amide. & The resist according to claim 2, wherein the amide is hydroxyalkylpyrrolidone. The resist according to claim 2, wherein the amide is hydroxyalkyl-ε-caprolactam. K The resist according to claim 2, wherein the amide is hydroxyethylpyrrolidone, hydroxypropylpyrrolidone, hydroxybutylpyrrolidone, human tetraxyethyl-ε-caprolactam, hydroxypropyl-ε-caprolactam or hydroxybutyl-ε-caprolactam. 6. The resist according to claim 1, wherein the N-hydroxyalkylamide is an N-hydroxyalkyl linear amide. 7. The resist according to claim 6, wherein the amide is N-hydroxyethylpyrrolidoneamide over N-hydroxyethylacetamide. & The resist according to claim 1, wherein the N-aminoalkylamide is an N-aminoalkyl cyclic amide. 9. The resist according to claim 8, wherein the amide is aminoalkylpyrrolidone. 10. The resist according to claim 8, wherein the amide is aminoalkyl-ε-cabrolactam. 11 The amide is aminoethylpyrrolidone, aminopropylpyrrolidone, aminobutylpyrrolidone, or aminoethyl-ε-caprolactam. Aminopropyl-ε-caprolactam-! ! Claim 8, which is bamboo aminobutyl-ε-caprolactam.
Resist written in the ode. Section 1. The resist according to claim 1, wherein the N-aminoalkylamide is an N-aonoalkyl linear amide. 1& The resist according to claim 2, wherein the amide is N-aminoethyl acetamide or FiN-aminoethylpropionamide. 14 The terminal unsaturated alcohol is hydroxyethyl acrylate, hydroxyethyl methacrylate, or 8-hydroxypropyl acrylate. 3-hydroxypropyl methacrylate, 4-acrylic acid
The resist according to claim 1, which is -°hydroxybutyl or 4-human tetraxybutyl methacrylate. 15. The reaction product from the compound selected from the group consisting of N-hydroxyalkylamides and N-aminoalkylamides and the reaction product from the terminally unsaturated alcohol have a ratio of about 410:60 to 60:40 to each other. 2. The resist of claim 1, present in said combination in molar ratios. 16 The N-hydroxyalkylamide and N-
A claim wherein the reaction product from the compound selected from the group consisting of aminoalkylamides and the reaction product from the terminally unsaturated alcohol are present in said combination in a molar ratio of about 10:90 to 90:10 to each other. range 1
Resist as described in section. 17 The N-hydroxyalkylamide and N-
Claims wherein the reaction product from the compound selected from the group consisting of agnoalkylamides and the reaction product from the terminally unsaturated alcohol are present in said combination in a molar ratio of about 50:50 to each other. The resist described in Range 1. 18. The resist 01g of claim 1, wherein the alkyl group of the alkyl vinyl ether-maleic anhydride copolymer is a long chain alkyl group. Claim 1, wherein the alkyl group has about 10 to 20 carbon atoms. 18th
Resist as described in section. 20. The resist according to claim 18, wherein the alkyl group is octadecyl.